Since a design of an organic light-emitting diode (OLED) pixel adopts a current-controlled type mostly, threshold voltages (Vth) of driving transistors of respective pixel units inside an entire panel are non-uniform and Vth offset produced after operation for a long period would reduce uniformity of displaying of the panel. Therefore, the above problem is avoided from occurring through a Vth compensation pixel design. In order to raise a process integration of an OLED display panel and at the same time reduce the cost, adopting gate driver on array (GOA) technology is a development trend in the future. However, the Vth compensation pixel design of OLED needs a peripheral gate driving circuit to cooperate therewith to provide a driving signal for performing the Vth compensation process. Therefore, a high requirement is set forth for the gate driving circuit.
In general, Vth compensation of pixels can be divided into threshold compensation within pixels and threshold compensation outside pixels. The way of compensation outside pixels is to provide a compensating signal to the pixels by disposing a threshold compensating unit outside the pixels. However, in the process of the threshold compensation, a peripheral gate driving circuit is needed to provide a matched gate driving signal.